Minor updates, improvements, and bug fixes.

- Allowed status_message function to be called by others. This is to
centralize all feedback into protocol.c.

- Fixed a bug where line number words 'N' were causing the parser to
error out.

- Allowed homing routine feed rates to move slower than the
MINIMUM_STEP_RATE parameter in config.h.

- Homing performs idle lock at the end of the routine.

- Stepper idle lock time will now not disable the steppers when the
value is set at 255. This is accomodate users who prefer to keep their
axes enabled at all times.

- Moved some defines around to where they need to be.

settings.c

@@ -105,6 +105,10 @@ void settings_reset(bool reset_all) {
   settings.decimal_places = DEFAULT_DECIMAL_PLACES;
 }
 
+// static void settings_startup_string(char *buf) {
+//   memcpy_from_eeprom_with_checksum((char*)buf,512, 4);
+// }
+
 void settings_dump() {
   printPgmString(PSTR("$0 = ")); printFloat(settings.steps_per_mm[X_AXIS]);
   printPgmString(PSTR(" (steps/mm x)\r\n$1 = ")); printFloat(settings.steps_per_mm[Y_AXIS]);
@@ -124,12 +128,18 @@ void settings_dump() {
   printPgmString(PSTR(" (milliseconds homing debounce delay)\r\n$14 = ")); printInteger(settings.stepper_idle_lock_time);
   printPgmString(PSTR(" (milliseconds stepper idle lock time)\r\n$15 = ")); printInteger(settings.decimal_places);
   printPgmString(PSTR(" (float decimal places)")); 
+  
+//   char buf[4];
+//   settings_startup_string((char *)buf);
+//   printPgmString(PSTR("\r\n Startup: ")); printString(buf);
+  
   printPgmString(PSTR("\r\n'$x=value' to set parameter or just '$' to dump current settings\r\n"));
 }
 
 // Parameter lines are on the form '$4=374.3' or '$' to dump current settings
 uint8_t settings_execute_line(char *line) {
   uint8_t char_counter = 1;
+//  unsigned char letter;
   float parameter, value;
   if(line[0] != '$') { 
     return(STATUS_UNSUPPORTED_STATEMENT); 
@@ -137,6 +147,23 @@ uint8_t settings_execute_line(char *line) {
   if(line[char_counter] == 0) { 
     settings_dump(); return(STATUS_OK); 
   }
+//   if(line[char_counter] >= 'A' || line[char_counter] <= 'Z') {
+//     letter = line[char_counter++];
+//     if(line[char_counter++] != '=') { 
+//       return(STATUS_UNSUPPORTED_STATEMENT); 
+//     }
+//     for (char_counter = 0; char_counter < LINE_BUFFER_SIZE-3; char_counter++) {
+//       line[char_counter] = line[char_counter+3];
+//     }
+//     uint8_t status = gc_execute_line(line);
+//     if (status) { return(status); }
+//     else { settings_store_startup_line(line); }
+//     
+//     
+//     // Opt stop and block delete are referred to as switches.
+//     // How to store home position and work offsets real-time??
+//     
+//   } else {
   if(!read_float(line, &char_counter, &parameter)) {
     return(STATUS_BAD_NUMBER_FORMAT);
   };
@@ -151,11 +178,16 @@ uint8_t settings_execute_line(char *line) {
   }
   settings_store_setting(parameter, value);
   return(STATUS_OK);
+//   }
 }
 
 void write_settings() {
   eeprom_put_char(0, SETTINGS_VERSION);
   memcpy_to_eeprom_with_checksum(1, (char*)&settings, sizeof(settings_t));
+//   
+//   char buf[4]; buf[0] = 'G'; buf[1] = '2'; buf[2] = '0'; buf[3] = 0;
+//   memcpy_to_eeprom_with_checksum(512, (char*)buf, 4);
+//   
 }
 
 int read_settings() {
@@ -254,5 +286,16 @@ void settings_init() {
     settings_reset(true);
     write_settings();
     settings_dump();
-  }
+  }  
 }
+
+// int8_t settings_execute_startup() {
+// 
+//   char buf[4];
+//   settings_startup_string((char *)buf);
+//   uint8_t i = 0;
+//   while (i < 4) {
+//     serial_write(buf[i++]);
+//   }
+//   return(gc_execute_line(buf));
+// }